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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Babu Moger <babu.moger@amd.com>,
        Sean Christopherson <seanjc@google.com>,
        Jim Mattson <jmattson@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.10 464/663] KVM: SVM: Intercept INVPCID when its disabled to inject #UD
Date:   Mon,  1 Mar 2021 17:11:52 +0100
Message-Id: <20210301161204.818021439@linuxfoundation.org>
In-Reply-To: <20210301161141.760350206@linuxfoundation.org>
References: <20210301161141.760350206@linuxfoundation.org>
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From: Sean Christopherson <seanjc@google.com>

[ Upstream commit 0a8ed2eaac102c746d8d114f2787f06cb3e55dfb ]

Intercept INVPCID if it's disabled in the guest, even when using NPT,
as KVM needs to inject #UD in this case.

Fixes: 4407a797e941 ("KVM: SVM: Enable INVPCID feature on AMD")
Cc: Babu Moger <babu.moger@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210212003411.1102677-2-seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/x86/kvm/svm/svm.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index f4ae3871e412a..76ab1ee0784ae 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1092,12 +1092,12 @@ static u64 svm_write_l1_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)
 static void svm_check_invpcid(struct vcpu_svm *svm)
 {
 	/*
-	 * Intercept INVPCID instruction only if shadow page table is
-	 * enabled. Interception is not required with nested page table
-	 * enabled.
+	 * Intercept INVPCID if shadow paging is enabled to sync/free shadow
+	 * roots, or if INVPCID is disabled in the guest to inject #UD.
 	 */
 	if (kvm_cpu_cap_has(X86_FEATURE_INVPCID)) {
-		if (!npt_enabled)
+		if (!npt_enabled ||
+		    !guest_cpuid_has(&svm->vcpu, X86_FEATURE_INVPCID))
 			svm_set_intercept(svm, INTERCEPT_INVPCID);
 		else
 			svm_clr_intercept(svm, INTERCEPT_INVPCID);
-- 
2.27.0